CV System Changes Flashcards
Functional Capacity and Normal Age-
related Physiological Declines
We cannot stop the aging process!what that can be done is giving more functional reserve
Healthy lifestyle can also bump themselves up
Trained adult at any age on a higher parallel aging curve than untrained
Functional Capacity and Normal Age-
related Physiological Declines
Independent functional reserve
Once you hit it you are no longer independent
Depending on your genetics you might not hit the line
3 component of the Cardiovascular system
Heart
Serves as a pump
3 component of the Cardiovascular system
Blood vessels
Passageways for blood to travel to all parts of the body and back to the heart
3 component of the Cardiovascular system
Blood
Transport medium
Main goal of the Cardiovascular system is to transport material throughout the body
Hypertension Stages
Normal
Mean SBP/DBP < 120/80 mmhg
Hypertension Stages
Elevated
(Previously pre-hypertension)
Mean SBP 120-129 mmHg and DBP <80 mmHg
Hypertension Stages
Stage 1 hypertension (Previously pre-hypertension)
Mean SBP 130-139 mmHg or mean DBP 80-89 mmHg
Hypertension Stages
Stage 2 hypertension
(Previously hypertension)
Mean SBP ≥ 140 mmHg OR
Mean DBP ≥ 90 mmHg OR
Self-reported use of medication for high blood pressure within the past month OR
Self-reported having been diagnosed with hypertension by a health-care professional
Systolic blood pressure (SBP)
Pressure exerted when heart beats and pumps blood
Diastolic blood pressure
Pressure exerted when heart rest
CV System – Structural Changes
Thickening (Arteries)
Thickening of the walls of the large arteries
With age the internal layer (tunica intima) of the artery thickens and fragments – a process similar to what happens with early
stage atherosclerosis
Even people with healthy heart show this,takes blame off older adults
2-3x the size of the artery
CV System – Structural Changes
Stiffness
Increased stiffness of the large arteries, small
arteries, and arterioles (less compliant)
With age the regulation of vasodilation is impaired (vessels are less responsive to biochemical cues for dilation)
Increased resistance = increased blood pressure
CV System – Structural Changes
Thickening (left ventricle)
Thickening of the walls of the left ventricle in response to thickening of the walls of the large arteries
Does physical activity
have an effect on
lowering blood
pressure in older
adults?
Heart can adapt from the amount of exercise done, increasing the functionality of the heart (stronger heart)
Postural hypotension/Orthostatic intolerance: changing position quickly leads to a decrease in blood pressure
Non pharmacological strategies to reduce blood pressure
The majority of non pharmalogical strategy to redce bp is exercise
3x a week for 3 months to see result
Any form of exercise, Aerobic or strength
Helps reconstruct ventricle walls
Heart rate definition
number of times the heart beats in one
minute
Heart Rate points
The average resting HR of older adults is not
significantly different from young adults
Maximum HR (associated with heavy exercise),
decreases 5-10 beats per minute each decade
Max HR calculation for individuals over 40 yrs:
208 - (0.7 x age)
Heart Rate points
The average resting HR of older adults is not
significantly different from young adults
Maximum HR (associated with heavy exercise),
decreases 5-10 beats per minute each decade
Max HR calculation for individuals over 40 yrs:
208 - (0.7 x age)
Sympathetic nerve
Reduced Sensitivity: The body becomes less responsive to norepinephrine, meaning the sympathetic nervous system is less activated during stress or exercise.
Receptor Changes: Adrenergic receptors (β-receptors) become less effective, leading to a reduced heart rate and contractility response during exertion.
Impaired Norepinephrine Uptake: Uptake mechanisms for norepinephrine may become less efficient, limiting cardiovascular adjustments during activity
Result: Older adults experience blunted cardiovascular responses, reduced exercise capacity, and slower recovery.
Does physical
activity have an effect
on max HR in
older adults?
Sedentary vs Endurance trained
There was no dramatic incline between both
Max heart rate is declining at the same rate no matter activity or not
Doesn’t change the sensitivity of the heart to norepinephrine
Stroke volume
the amount of blood (in ml) pumped
from the heart with each beat
How does resting supine stroke volume change with aging in men or women?
Resting supine stroke volume showed little change with
aging in men or women
How does stroke volume respond to increased activity with age?
Stroke volume changes in response to increased activity do not happen as efficiently with age due to several factors.
What factors contribute to less efficient stroke volume changes with age during increased activity?
Reduced heart muscle elasticity
Slower heart rate response to activity
Stiffer arteries
Decreased contractile function of the heart
Less efficient oxygen utilization
Cardiac Output –
the total amount of blood ejected from each ventricle of the heart in 1 min, expressed in litres per minute (L/min)
Cardiac Output = Stroke volume x Heart Rate
Q = SV x HR
How does cardiac output at rest compare between older and younger adults?
Cardiac output at rest is typically similar in both older and younger adults, as compensatory mechanisms maintain overall stability despite minor changes in stroke volume and heart rate.
How does cardiac output during exhaustive activity differ between older and younger adults?
Cardiac output during exhaustive activity is lower in older adults
Heart rate drops and you cannot offset Cardiac output with just that
What is the arterio-venous oxygen difference ((a-v)O2 difference)?
It is the difference between the amount of oxygen transported in the arterial blood and the amount of oxygen transported in the mixed venous blood.
What is the typical (a-v)O2 difference at rest and during maximal exercise?
At rest: ~5 ml O2/100 ml blood
During maximal exercise: ~15 ml O2/100 ml blood
How does the (a-v)O2 difference change with age?
The (a-v)O2 difference decreases with age. For example, a 65-year-old male has an (a-v)O2 difference 20-40% lower than a 25-year-old male
How does aging affect muscle oxygen extraction, and can training influence the (a-v)O2 difference?
With age, muscle becomes less effective at extracting oxygen and there is less muscle overall. However, a trained adult can improve their (a-v)O2 difference and become more effective at oxygen extraction through exercise.
What is VO2max, and how is it measured?
VO2max is the maximal rate at which oxygen can be taken up, distributed, and used by the body during exercise that engages a large muscle mass. It is measured in ml * kg⁻¹ * min⁻¹.
What is the formula for VO2max?
VO2max = Cardiac Output × (a-v)O2 difference
How does VO2max change with age, and why?
VO2max declines by about 1% per year after age 25. This decline is mainly due to a reduction in maximal heart rate.
VO2 max vs increase in age
for Women
(endurances-trained vs Sedentary)
10percent decline If individuals is sedentary
Sedentary are closer to that individual function (15)
(No longer independent)
VO2 max vs increase in age
for Men
(endurances-trained vs Active, Sedentary)
Rate of decline between groups are no different
End point is different
Absolute function levels are different
Train to increase stroke volume and. A.V p, ore muscle in heart
Cardiopulmonary System
The heart operates in partnership with the lungs toensure the efficient transport of blood to and from the heart to facilitate the exchange of oxygen and carbon
dioxide.
CP system – Structural Changes
Reduction in alveolar surface area
Loss of elastic recoil of the lungs
Increased chest wall stiffness
Decreased inspiratory muscle strength (e.g. diaphragm, intercostals)
Breathe less
Reduction in alveolar surface area
less surface area for
gas exchange to occur
Loss of elastic recoil of the lungs
increase work
required for respiration
Increased chest wall stiffness
increase work required
for respiration
Decreased inspiratory muscle strength (e.g. diaphragm, intercostals)
increase work required for respiration
Breathless
System is not keeping up
